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Need to convert a double-pole 240v to single-pole 120v for AC...

Need to convert a double-pole 240v to single-pole 120v for AC...

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  #1  
Old 06-24-17, 06:18 PM
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Need to convert a double-pole 240v to single-pole 120v for AC...

Hello everyone, I'm in a heatwave and my window AC keeps tripping the breakers. I've plugged it into the kitchen circuit and the living room circuit and with all the other appliances pulling power, it trips the breakers. The AC is a larger 10 or 12,000 BTU window unit that really needs its own circuit as the tag on it says it needs 15amps.

I have a 240v, 40amp, double-pole that powers the in wall heaters in the kitchen and living room. I simply want to add a 15amp outlet next to the living room heater and temporarily (until winter) have it wired using the heater circuit. I don't mind swapping it back when winter comes.

Is this simply a matter of removing the double-pole 240v/40amp breaker and installing a single 15amp breaker, connecting the black power wire to the breaker and the white neutral to the neutral bar? Would this result in the power at the wall heater being 120v/15amp?

I'm attaching pics of the box, living room heater and kitchen heater connections.

Breaker box - Album on Imgur
 
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Old 06-24-17, 07:17 PM
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Are you sure that nothing else is on that circuit?
 
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Old 06-24-17, 07:26 PM
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Correct. Just those two heaters.

There's an identical circuit for heaters in the bedrooms. It's directly to the right of the blue masking taped circuit. I currently have them both off in the pictures.
 
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Old 06-24-17, 07:46 PM
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Yes, I saw the pics but that doesn't tell me what else is on the circuit. It sounds doable to me bou might want to wait for one of the electrical experts here before you try it.
 
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Old 06-24-17, 08:05 PM
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Is this simply a matter of removing the double-pole 240v/40amp breaker and installing a single 15amp breaker, connecting the black power wire to the breaker and the white neutral to the neutral bar? Would this result in the power at the wall heater being 120v/15amp?
Yes that would work but you might as well use a 20 amp breaker. Assuming a duplex receptacle you can still use a 15 amp receptacle. Note you must have ground wire to meet code. The heater must be completely disconnected.
 
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Old 06-24-17, 08:17 PM
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Excellent, thanks for confirming. Off to Home Depot I go.
 
  #7  
Old 06-24-17, 10:22 PM
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Okay, maybe you can help again lol.

New breaker is installed and has power on the live line in the breaker box (using a Klein contact tester).

I already rigged up the receptacle and I had no power with a desk lamp.

The lines at the heaters are not live using the contact tester.

Here's a few pics of the heater cavities and the wires. I'm stumped.

http://imgur.com/a/INxcB
 

Last edited by jringo; 06-24-17 at 10:38 PM.
  #8  
Old 06-24-17, 10:38 PM
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using a Klein contact tester
Useless for determining if you have voltage. You need a multimeter or neon test light.

My first thought is you are on the wrong side of a thermostat. You need to connect where power first comes in before the thermostat.
 
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Old 06-24-17, 11:19 PM
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Thanks for the quick reply...and correct answer! lol

I pulled the thermostat cover off and checked for voltage and it's there. Since I had already had my receptacle box rigged up (and the desk lamp plugged in), I thought why not and turned the thermostat on and VIOLA! the desk light came on.

Now I'm not sure how to proceed.

Can I leaved my setup as it is and simply turn the thermostat on to power the outlet or ?

Thanks again!
 
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Old 06-24-17, 11:39 PM
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It may not hurt anything but it would be better to wire it correctly.
 
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Old 06-24-17, 11:42 PM
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That would be too tap directly into the lines and fish it down the wall and install the receptacle at proper height? Guess I need to pull a few more tools out lol.
 

Last edited by jringo; 06-25-17 at 12:24 AM.
  #12  
Old 06-25-17, 01:21 AM
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Just remember all connections need to be made in an accessible junction box.
 
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